The present invention relates generally to medical devices. More particularly, the present invention pertains to guiding a medical device within a patient, e.g., self-guiding a medical device for treating a patient.
Various medical devices are known which can be guided by a user within a patient. For example, guide wires may be manipulated to guide probes, catheters, leads, stents, etc., through various regions of a patient, e.g., arterial or venous pathways. Further, for example, shaped memory alloys may be moved, such as under control of electrical currents, and guided by a user to specific regions within a patient.
Various systems have been described which provide information to a user for use in guiding such medical devices. For example, cameras operating in a visible range, ultrasound techniques, fluoroscopy, magnetic resonance imaging (MRI), and positron emission tomography (PET), have all been proposed for use in guidance systems. For example, one fluoroscopy guidance system includes the observation of two flat real-time x-ray images acquired from different angles. Further, for example, in optical coherence tomography (OCT), a beam of light carried by an optical fiber may illuminate an area within the patient, e.g., the interior of an artery. In a radar-like manner, light reflected back into the fiber from features inside the artery is correlated with the emitted light to capture the depth as well as the angular separation of those features. The features are displayed graphically in two or three dimensions through the use of a suitably programmed computer. A user can then manually guide a working element through the patient with the benefit of the optical images obtained.
However, such systems are generally very large, complex and require expensive visualization techniques. Further, such systems generally do not have the ability to provide desired information with regard to local areas within the patient. For example, optical imaging may give a very efficient and effective physical structure for the region in which a medical device is being guided by the user. However, it is generally not adequate for making distinctions between local areas within the region in which the medical device is guided. For example, optical images may not be adequate to show where the coronary sinus is within the heart; may not be able to provide adequate identification of early atherosclerosis or calcified tissue within the patient; may not be able to be used to identify particular substances within the region; etc. Generally, such optical imaging is only adequate for providing physical structure of the region in which the medical device is being guided by the user. Furthermore, such imaging systems and devices require an external reference point and/or a user, such as a medical technician, to guide the devices.
The present invention utilizes imaging in the guidance of medical devices such as, for example, cardiac leads, neural stimulating electrodes, drug delivery catheters, stents, ablation catheters, etc. In one particular embodiment, the imaging (e.g., chemical imaging) is used to identify a target area within a region of a patient. A medical device is guided (e.g., self-guided) based on the detected target area.
A method of guiding a medical device within a patient according to the present invention includes acquiring image data of a view region within a region of the patient. The image data generally includes a plurality of image data pixel elements. Each data pixel element is representative of at least one characteristic of a portion within the view region. A movable element of the medical device is self-guided based on the image data.
In one embodiment of the method, the guiding of the movable element is performed by analyzing the image data to detect a target area within the view region based on the plurality of image data pixel elements. The target area includes one or more image data pixel elements having at least one characteristic that is different from other image data pixel elements representative of other portions within the view region. The movable element of the medical device is then self-guided based on the detected target area.
In one embodiment of the method, the characteristic includes at least one of a chemical, physical, mechanical, electrical, thermal, or physiological characteristic.
Another method of guiding a medical device within a patient according to the present invention includes acquiring chemical image data of a view region within the patient. The chemical image data generally includes a plurality of chemical image data pixel elements. Each data pixel element is representative of at least one chemical characteristic (e.g., at least one chemical composition characteristic and/or at least one chemical structure characteristic) of a portion within the view region. A movable element of the medical device is guided based on the chemical image data (e.g., self-guided without user intervention and/or user guided based on a displayed chemical image).
In one embodiment of the method, the guiding of the movable element is performed by analyzing the chemical image data to detect a target area within the view region based on the plurality of chemical image data pixel elements. The target area includes one or more chemical image data pixel elements having at least one chemical characteristic that is different from other chemical image data pixel elements representative of other portions within the view region. The movable element of the medical device is then guided based on the detected target area.
Further, in various embodiments of the methods above, the acquiring of the image data may include sensing natural detectable properties (e.g., the emission of electromagnetic radiation from the view, region or chemical concentration gradients from the view region), and/or certain detectable properties representative of a characteristic may be caused to be exhibited (e.g., via an excitation source such as visual stimuli or chemical stimuli) and thereafter sensed. For example, detectable properties may include electromagnetic radiation, electrical signal activity, mechanical activity, chemical composition properties, chemical structural properties, chemical release properties, etc.
In another embodiment of the methods, physical structure image data representative of the physical structure of the view region is provided in addition to chemical image data. In this embodiment, the guiding, e.g., self-guiding, of the movable element is performed based on the chemical image data and the physical structure image data.
In another embodiment of the methods, image data for a number of view regions is used to generate stored image data, e.g., for a much larger region. For example, such stored image data for a much larger region may be used for comparison purposes with respect to image data acquired at a later time for such view regions.
A guided medical device system according to the present invention is also described. The medical device system includes a movable element of a medical device and a motion control apparatus operatively connected to control motion of the movable element. At least one sensor is associated with the movable element and is operable to acquire image data of a view region within a patient. The image data includes a plurality of image data pixel elements. Each data pixel element is representative of at least one characteristic of a portion within the view region. A computing apparatus is operatively connected to the at least one sensor to receive image data. The computing apparatus generates an output based on the image data. The movable element is self-guided using the motion control apparatus in response to the output based on the image data.
In one embodiment of the system, the computing apparatus is operable to analyze the image data to detect a target area within the view region based on the image data pixel elements. The target area includes one or more image data pixel elements having at least one characteristic that is different from other image data pixel elements representative of the other portions within the view region. The computing apparatus provides an output to the motion control apparatus based on the detected target area.
Another guided medical device system according to the present invention is also described. The medical device system includes a movable element of a medical device and a motion control apparatus operatively connected to control motion of the movable element. At least one sensor is associated with the movable element and is operable to acquire chemical image data of a view region within a patient. The chemical image data includes a plurality of chemical image data pixel elements. Each data pixel element is representative of at least one chemical characteristic of a portion within the view region. A computing apparatus is operatively connected to the at least one sensor to receive chemical image data. The computing apparatus generates an output based on the chemical image data for use in guiding the movable element, e.g., self-guided without user intervention and/or user guided based on a displayed chemical image.
In one embodiment of the system described above, the computing apparatus is operable to analyze the chemical image data to detect a target area within the view region based on the chemical image data pixel elements. The target area includes one or more chemical image data pixel elements having at least one chemical characteristic that is different from other chemical image data pixel elements representative of the other portions within the view region. The computing apparatus provides an output to the motion control apparatus based on the detected target area.
Further, with regard to the methods and systems described herein, the methods and systems may include delivering treatment to a portion of the view area within the patient, e.g., the detected target area. For example, the treatment may be delivered by one of a cardiac lead, a stimulating electrode, a drug delivery catheter, a #tent, an ablation catheter, or any other medical device.